This task tracks putting netmon1003 (Bullseye) in service.
Outline of steps:
* [X] Validate in Poonton that puppet runs cleanly in Bullseye, and all services are up
* [X] Add prometheus-atlas-exporter for Bullseye in reprepo.
* [X] Ensure LibreNMS dependencies are installed for Bullseye https://gerrit.wikimedia.org/r/c/operations/puppet/+/810106/
* [x] Update ACLs on network devices, via capirca https://wikitech.wikimedia.org/wiki/Homer#Capirca_%28ACL_generation%29
* [x] Add suppport for multiple backup/passive nodes in Puppet https://gerrit.wikimedia.org/r/c/operations/puppet/+/814848
* [x] Set netmon1003 as backup/standby netmon host
* [x] Apply role::netmon to new host
*  Confirm new host has DB privileges
*  Determine what (if any) data should to be carried over from netmon1002 to netmon1003
*  Failover to netmon1003
*  Flip DNS for LibreNMS and Smokeping from netmon1002 to netmon1003 https://gerrit.wikimedia.org/r/c/operations/dns/+/819177
*  Add the new host as a syslog destination in homer `templates/common/system.conf` https://gerrit.wikimedia.org/r/c/operations/homer/public/+/819124
*  Set netmon1003 as as `netmon_server` and netmon1002 as `netmon_servers_failover` in the Puppet repository.
cc #netops, feel free to edit as needed if I missed something